.container {
  width: 95%;
  margin: auto;
}

.course-title {
  margin: 50px 0 7px 20px;
  font-family: var(--evidence-font);
  font-size: 30px;
}

.course-subtitle {
  margin: 0 0 20px 20px;
  color: var(--text-secondary);
  font-family: var(--evidence-font);
  font-size: 20px;
}

.tech-section {
  display: flex;
  gap: 50px;
  padding: 30px;
  border: var(--border-standard);
  border-radius: 20px;
  background: var(--bg-content-card);
  box-shadow: var(--shadow-dark);
}

.meta-section {
  flex: 1;
  display: flex;
  gap: 40px;
}

.description-section {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.image-container img {
  max-width: 280px;
  width: 100%;
  height: auto;
  border-radius: 20px;
  box-shadow: var(--shadow-hero-card);
  filter: var(--image-filter);
}

.meta-container {
  display: flex;
  align-items: center;
}

.meta-container ul {
  margin: 0;
  list-style-type: none;
  padding: 0;
}

.meta-container li {
  margin-top: 10px;
  padding-bottom: 4px;
  border-bottom: var(--border-standard);
}

.key-span {
  margin-right: 10px;
  color: var(--text-muted);
  font-size: 19px;
  font-weight: 500;
}

.key-value {
  color: var(--text-secondary);
  font-size: 17px;
  font-weight: 100;
}

.key-value.price {
  color: var(--text-accent-blue);
  font-size: 20px;
  font-weight: bolder;
}

.description-section p {
  color: var(--text-secondary);
  font-size: 18px;
  line-height: 1.2;
}

.description-section p:last-child {
  color: var(--text-muted);
  font-size: 17px;
}

.divider-band {
  width: 100%;
  height: 80px;
  margin: 40px 0 0 0;
  background: linear-gradient(
    to bottom,
    transparent,
    rgba(255,255,255,0.03),
    transparent
  );
}

.content-section {
  display: flex;
  gap: 40px;
  padding: 0 10px 40px 10px;
}

.lessons-container {
  flex: 1.3;
  display: flex;
  flex-direction: column;
  padding: 40px 40px 0 40px;
}

.banner-container {
  flex: 0.7;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 50px;
  margin-top: 180px;
  padding: 20px;
}

.lessons-title {
  margin-top: 0;
  margin-bottom: 5px;
  text-align: center;
  font-family: var(--evidence-font);
  font-size: 28px;
}

.lessons-text {
  margin-top: 0;
  margin-bottom: 0;
  text-align: center;
  color: var(--text-secondary);
  font-size: 18px;
}

.lessons-accordion {
  max-height: 1000px;
  margin-top: 30px;
  padding: 20px;
  overflow-y: auto;
  scrollbar-width: none;
}
.lessons-accordion::-webkit-scrollbar {
  display: none;
}

.accordion-item {
  position: relative;
  padding-left: 100px;
  margin-bottom: 80px;
}

.accordion-item::before {
  content: "";
  position: absolute;
  left: 35px;
  top: 60px;
  height: calc(100% + 60px);
  bottom: -30px;
  width: 2px;
  background: linear-gradient(to bottom, rgba(59,130,246,0.8), rgba(59,130,246,0.3));
  box-shadow: 0 0 6px rgba(59,130,246,0.6);
}
.accordion-item:last-child::before {
  display: none;
}

.accordion-header {
  display: flex;
  align-items: center;
  cursor: pointer;
  padding: 20px 0;
}

.accordion-number {
  display: flex;
  align-items: center;
  justify-content: center;
  position: absolute;
  left: 0;
  width: 70px;
  height: 70px;
  border: var(--border-card-blue);
  border-radius: 50%;
  color: var(--text-accent-blue);
  background: var(--bg-hero);
  font-size: 18px;
  font-weight: bold;
  z-index: 2;
  box-shadow: var(--shadow-blue-off);
}

.accordion-title {
  flex: 1;
  color: var(--text-secondary);
  font-size: 18px;
  font-weight: 500;
}

.accordion-icon {
  color: var(--text-accent-blue);
  transition: 0.3s;
}

.accordion-item.active .accordion-icon {
  transform: rotate(180deg);
}

.accordion-item.active .accordion-title {
  color: var(--text-primary);
}

.accordion-item.active .accordion-number {
  box-shadow: var(--shadow-blue-on);
}

.accordion-content {
  display: flex;
  flex-direction: column;
  max-height: 0;
  overflow: hidden;
  transition: 0.4s ease;
}

.accordion-item.active .accordion-content {
  max-height: 1000px;
}

.lesson-container {
  display: flex;
  padding: 12px 0;
  border-top: var(--border-standard);
}

.lesson-left {
  flex: 0.2;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 10px;
  padding: 10px;
  border-right: var(--border-standard);
}

.lesson-center {
  flex: 1.3;
  display: flex;
  align-items: center;
  padding: 10px;
}

.lesson-right {
  flex: 0.2;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: end;
  gap: 10px;
  padding: 10px;
}

.lesson-number {
  margin-top: 0;
  margin-bottom: 0;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
}

.lesson-duration {
  padding: 2px 12px;
  border-radius: 4px;
  color: var(--text-accent-blue);
  background: rgba(34,197,94,0.1);
  font-size: 14px;
  font-weight: 200;
}

.lesson-title {
  margin-top: 0;
  margin-bottom: 0;
  font-size: 16px;
  font-weight: 500;
}

.lesson-right button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  white-space: nowrap;
  min-width: max-content;
  width: 90px;
  line-height: 1;
  padding: 4px 10px;
  border: var(--border-button-outline);
  border-radius: 10px;
  color: var(--text-accent-blue);
  background: transparent;
  font-size: 13px;
  font-weight: 100;
  text-decoration: none;
  box-shadow: var(--shadow-blue-off);
  transition: 0.3s;
}
.lesson-right button:hover {
  transform: translateY(-3px);
  color: var(--text-primary);
  background: var(--bg-button-outline-on);
  box-shadow: var(--shadow-blue-on);
}

/* laptop 1600–1919px */
@media (min-width: 1600px) and (max-width: 1919px) {
  .course-title {
    margin: 40px 0 7px 20px;
    font-size: 26px;
  }

  .course-subtitle {
    font-size: 17px;
  }

  .tech-section {
    padding: 20px;
  }

  .image-container img {
    max-width: 260px;
  }

  .key-span {
    font-size: 18px;
  }

  .key-value {
    font-size: 16px;
  }

  .key-value.price {
    font-size: 19px;
  }

  .description-section p {
    font-size: 17px;
  }

  .description-section p:last-child {
    font-size: 16px;
  }

  .divider-band {
    height: 60px;
  }

  .content-section {
    gap: 30px;
  }

  .lessons-container {
    padding: 30px 30px 0 30px;
  }

  .banner-container {
    gap: 40px;
    margin-top: 160px;
  }

  .lessons-title {
    font-size: 26px;
  }

  .lessons-text {
    font-size: 17px;
  }

  .lessons-accordion {
    margin-top: 20px;
  }

  .accordion-item {
    padding-left: 90px;
  }

  .accordion-item::before {
    left: 30px;
  }

  .accordion-number {
    font-size: 17px;
  }

  .accordion-title {
    font-size: 17px;
  }

  .lesson-title {
    font-size: 15px;
  }

  .lesson-right button {
    width: 80px;
    padding: 4px 8px;
    font-size: 12px;
  }
}

/* laptop 1366–1599px */
@media (min-width: 1366px) and (max-width: 1599px) {
  .course-title {
    margin: 40px 0 7px 20px;
    font-size: 24px;
  }

  .course-subtitle {
    font-size: 15px;
  }

  .tech-section {
    gap: 40px;
    padding: 20px;
  }

  .meta-section {
    gap: 30px;
  }

  .image-container img {
    max-width: 230px;
  }

  .key-span {
    font-size: 17px;
  }

  .key-value {
    font-size: 15px;
  }

  .key-value.price {
    font-size: 18px;
  }

  .description-section p {
    margin-top: 0;
    margin-bottom: 15px;
    font-size: 16px;
  }

  .description-section p:last-child {
    margin-top: 0;
    margin-bottom: 0;
    font-size: 15px;
  }

  .divider-band {
    height: 50px;
    margin: 30px 0 0 0;
  }

  .content-section {
    gap: 0;
    padding: 0 20px 40px 20px;
  }

  .lessons-container {
    flex: 1;
  }

  .banner-container {
    display: none;
  }

  .lessons-title {
    font-size: 24px;
  }

  .lessons-text {
    font-size: 17px;
  }

  .lessons-accordion {
    max-height: 700px;
    margin-top: 20px;
  }

  .accordion-item {
    padding-left: 90px;
    margin-bottom: 70px;
  }

  .accordion-item::before {
    left: 30px;
  }

  .accordion-number {
    width: 60px;
    height: 60px;
    font-size: 17px;
  }

  .accordion-title {
    font-size: 17px;
  }

  .lesson-title {
    font-size: 15px;
  }
}

/* laptop 1280–1365px */
@media (min-width: 1280px) and (max-width: 1365px) {
  .course-title {
    margin: 40px 0 7px 20px;
    font-size: 24px;
  }

  .course-subtitle {
    font-size: 15px;
  }

  .tech-section {
    gap: 40px;
    padding: 20px;
  }

  .meta-section {
    gap: 30px;
  }

  .image-container img {
    max-width: 230px;
  }

  .key-span {
    font-size: 16px;
  }

  .key-value {
    font-size: 15px;
  }

  .key-value.price {
    font-size: 17px;
  }

  .description-section p {
    margin-top: 0;
    margin-bottom: 12px;
    font-size: 15px;
  }

  .description-section p:last-child {
    margin-top: 0;
    margin-bottom: 0;
    font-size: 14px;
  }

  .divider-band {
    height: 50px;
    margin: 30px 0 0 0;
  }

  .content-section {
    gap: 0;
    padding: 0 10px 30px 10px;
  }

  .lessons-container {
    flex: 1;
    padding: 40px 20px 0 20px;
  }

  .banner-container {
    display: none;
  }

  .lessons-title {
    font-size: 24px;
  }

  .lessons-text {
    font-size: 17px;
  }

  .lessons-accordion {
    max-height: 700px;
    margin-top: 20px;
  }

  .accordion-item {
    padding-left: 90px;
    margin-bottom: 70px;
  }

  .accordion-item::before {
    left: 30px;
  }

  .accordion-number {
    width: 60px;
    height: 60px;
    font-size: 17px;
  }

  .accordion-title {
    font-size: 17px;
  }

  .lesson-title {
    font-size: 15px;
  }
}

/* tablet */
@media (min-width: 768px) and (max-width: 1279px) and (orientation: portrait) {
  .course-title {
    margin: 30px 0 7px 20px;
    text-align: center;
    font-size: 26px;
  }

  .course-subtitle {
    text-align: center;
    font-size: 16px;
  }

  .tech-section {
    flex-direction: column;
    gap: 20px;
    padding: 20px;
  }

  .image-container img {
    max-width: 240px;
  }

  .key-span {
    font-size: 17px;
  }

  .key-value {
    font-size: 15px;
  }

  .key-value.price {
    font-size: 18px;
  }

  .description-section p {
    margin-top: 0;
    margin-bottom: 15px;
    font-size: 17px;
  }

  .description-section p:last-child {
    margin-top: 0;
    margin-bottom: 0;
    font-size: 16px;
  }

  .divider-band {
    height: 40px;
    margin: 20px 0 0 0;
  }

  .content-section {
    gap: 0;
    padding: 0 10px 30px 10px;
  }

  .lessons-container {
    flex: 1;
    padding: 40px 10px 0 10px;
  }

  .banner-container {
    display: none;
  }

  .lessons-title {
    font-size: 26px;
  }

  .lessons-text {
    font-size: 17px;
  }

  .lessons-accordion {
    max-height: 500px;
    margin-top: 20px;
  }

  .accordion-item {
    padding-left: 65px;
    margin-bottom: 60px;
  }

  .accordion-item::before {
    left: 25px;
  }

  .accordion-number {
    width: 50px;
    height: 50px;
    font-size: 16px;
  }

  .accordion-title {
    font-size: 16px;
  }

  .lesson-left {
    flex: 0.3;
  }

  .lesson-number {
    font-size: 13px;
  }

  .lesson-duration {
    font-size: 13px;
  }

  .lesson-title {
    font-size: 14px;
  }

  .lesson-right button {
    width: 80px;
    padding: 4px 8px;
    font-size: 12px;
  }
}
@media (min-width: 768px) and (max-width: 1279px) and (orientation: landscape) {
  .course-title {
    margin: 40px 0 7px 20px;
    font-size: 26px;
  }

  .course-subtitle {
    font-size: 18px;
  }

  .tech-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
    padding: 20px;
  }

  .meta-section {
    flex: 1;
    display: flex;
    gap: 80px;
  }

  .image-container img {
    max-width: 260px;
  }

  .key-span {
    font-size: 17px;
  }

  .key-value {
    font-size: 15px;
  }

  .key-value.price {
    font-size: 18px;
  }

  .description-section p {
    margin-top: 0;
    margin-bottom: 15px;
    font-size: 17px;
  }

  .description-section p:last-child {
    margin-top: 0;
    margin-bottom: 0;
    font-size: 17px;
  }

  .divider-band {
    height: 40px;
    margin: 30px 0 0 0;
  }

  .content-section {
    gap: 0;
    padding: 0 10px 20px 10px;
  }

  .lessons-container {
    flex: 1;
    padding: 40px 30px 0 30px;
  }

  .banner-container {
    display: none;
  }

  .lessons-title {
    font-size: 26px;
  }

  .lessons-text {
    font-size: 17px;
  }

  .lessons-accordion {
    max-height: 500px;
    margin-top: 20px;
  }

  .accordion-item {
    padding-left: 80px;
    margin-bottom: 60px;
  }

  .accordion-item::before {
    left: 25px;
  }

  .accordion-number {
    width: 50px;
    height: 50px;
    font-size: 16px;
  }

  .accordion-title {
    font-size: 16px;
  }

  .lesson-number {
    font-size: 13px;
  }

  .lesson-duration {
    font-size: 13px;
  }

  .lesson-title {
    font-size: 15px;
  }

  .lesson-right button {
    width: 80px;
    padding: 4px 8px;
    font-size: 12px;
  }
}

/* smartphone */
@media (max-width: 767px) and (orientation: portrait) {
  .course-title {
    margin: 30px 0 7px 20px;
    text-align: center;
    font-size: 20px;
  }

  .course-subtitle {
    text-align: center;
    font-size: 14px;
  }

  .tech-section {
    flex-direction: column;
    gap: 20px;
    padding: 10px;
  }

  .meta-section {
    flex-direction: column;
    align-items: center;
    gap: 10px;
  }

  .description-section {
    flex: 1;
  }

  .image-container {
    display: flex;
    justify-content: center;
  }

  .image-container img {
    max-width: 98%;
  }

  .key-span {
    margin-right: 8px;
    font-size: 16px;
  }

  .key-value {
    font-size: 14px;
  }

  .key-value.price {
    font-size: 17px;
  }

  .description-section p {
    margin-top: 0;
    margin-bottom: 15px;
    text-align: center;
    font-size: 16px;
    line-height: 1.1;
  }

  .description-section p:last-child {
    margin-top: 0;
    margin-bottom: 0;
    text-align: center;
    font-size: 14px;
  }

  .divider-band {
    height: 40px;
    margin: 20px 0 0 0;
  }

  .content-section {
    gap: 0;
    padding: 0 10px 30px 10px;
  }

  .lessons-container {
    flex: 1;
    max-width: 95%;
    padding: 30px 10px 0 10px;
  }

  .banner-container {
    display: none;
  }

  .lessons-title {
    font-size: 20px;
  }

  .lessons-text {
    font-size: 15px;
  }

  .lessons-accordion {
    max-height: 300px;
    margin-top: 20px;
    padding: 10px;
  }

  .accordion-item {
    padding-left: 50px;
    margin-bottom: 50px;
  }

  .accordion-item::before {
    left: 20px;
  }

  .accordion-number {
    width: 40px;
    height: 40px;
    font-size: 14px;
  }

  .accordion-title {
    font-size: 14px;
  }

  .lesson-container {
    flex-direction: column;
  }

  .lesson-left {
    flex: 1;
    flex-direction: row;
    gap: 20px;
    border-right: none;
  }

  .lesson-center {
    flex: 1;
  }

  .lesson-right {
    flex: 1;
    flex-direction: row;
    justify-content: center;
    align-items: center;
  }

  .lesson-number {
    font-size: 15px;
  }

  .lesson-duration {
    padding: 2px 10px;
  }

  .lesson-title {
    text-align: center;
    font-size: 14px;
  }

  .lesson-right button {
    padding: 4px 8px;
  }
}
@media (max-width: 767px) and (orientation: landscape) {
  .course-title {
    margin: 30px 0 7px 20px;
    text-align: center;
    font-size: 20px;
  }

  .course-subtitle {
    text-align: center;
    font-size: 15px;
  }

  .tech-section {
    flex-direction: column;
    gap: 20px;
    padding: 10px;
  }

  .meta-section {
    gap: 30px;
  }

  .image-container img {
    max-width: 230px;
  }

  .key-span {
    margin-right: 7px;
    font-size: 16px;
  }

  .key-value {
    font-size: 15px;
  }

  .key-value.price {
    font-size: 17px;
  }

  .description-section p {
    margin-top: 0;
    margin-bottom: 15px;
    font-size: 16px;
  }

  .description-section p:last-child {
    margin-top: 0;
    margin-bottom: 0;
    font-size: 15px;
  }

  .divider-band {
    height: 40px;
    margin: 20px 0 0 0;
  }

  .content-section {
    gap: 0;
    padding: 0 10px 30px 10px;
  }

  .lessons-container {
    flex: 1;
    padding: 40px 10px 0 10px;
  }

  .banner-container {
    display: none;
  }

  .lessons-title {
    font-size: 20px;
  }

  .lessons-text {
    font-size: 16px;
  }

  .lessons-accordion {
    max-height: 500px;
    margin-top: 20px;
    padding: 10px;
  }

  .accordion-item {
    padding-left: 60px;
    margin-bottom: 40px;
  }

  .accordion-item::before {
    left: 20px;
  }

  .accordion-number {
    width: 40px;
    height: 40px;
    font-size: 15px;
  }

  .accordion-title {
    font-size: 15px;
  }

.lesson-container {
  display: flex;
  padding: 12px 0;
  border-top: var(--border-standard);
}

  .lesson-left {
    flex: 0.4;
  }

  .lesson-number {
    font-size: 13px;
  }

  .lesson-duration {
    padding: 2px 10px;
    font-size: 13px;
  }

  .lesson-title {
    font-size: 14px;
  }

  .lesson-right button {
    width: 80px;
    padding: 4px 8px;
    font-size: 12px;
  }
}
@media (min-width: 768px) and (max-width: 915px) and (max-height: 500px) and (orientation: landscape) {
  .course-title {
    margin: 30px 0 7px 20px;
    font-size: 22px;
  }

  .course-subtitle {
    font-size: 16px;
  }

  .tech-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
    padding: 20px;
  }

  .meta-section {
    flex: 1;
    display: flex;
    gap: 80px;
  }

  .image-container img {
    max-width: 240px;
  }

  .key-span {
    font-size: 17px;
  }

  .key-value {
    font-size: 15px;
  }

  .key-value.price {
    font-size: 18px;
  }

  .description-section p {
    margin-top: 0;
    margin-bottom: 15px;
    font-size: 16px;
  }

  .description-section p:last-child {
    margin-top: 0;
    margin-bottom: 0;
    font-size: 15px;
  }

  .divider-band {
    height: 40px;
    margin: 30px 0 0 0;
  }

  .content-section {
    gap: 0;
    padding: 0 10px 20px 10px;
  }

  .lessons-container {
    flex: 1;
    padding: 40px 20px 0 20px;
  }

  .banner-container {
    display: none;
  }

  .lessons-title {
    font-size: 22px;
  }

  .lessons-text {
    font-size: 16px;
  }

  .lessons-accordion {
    max-height: 500px;
    margin-top: 20px;
  }

  .accordion-item {
    padding-left: 70px;
    margin-bottom: 60px;
  }

  .accordion-item::before {
    left: 25px;
  }

  .accordion-number {
    width: 50px;
    height: 50px;
    font-size: 16px;
  }

  .accordion-title {
    font-size: 16px;
  }

  .lesson-number {
    font-size: 12px;
  }

  .lesson-duration {
    font-size: 12px;
  }

  .lesson-title {
    font-size: 13px;
  }

  .lesson-right button {
    width: 80px;
    padding: 4px 8px;
    font-size: 12px;
  }
}